Fuse-box of molded insulation.



PIATENTED MAY 28, 1907.

A. G. SAVAGE. FUSE BOX 0P MOLDED INSULATION.

APPLIOATION FILED JUNE 12, 1905.

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rm m mzm mvc v 1W h n wflm UNITED sr rEs PATENT OFFICE.

ARTHUR o. SAVAGE-OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

FUSE-BOX OF MOLDED INSULATION.

Patented May 28, 1907.

Applicationilled June 12, 1905. Serial No. 264,819-

To a whom it may concern:

Be it known. that I, ARTHUR O. SAVAGE, .,.a' citizen of the United States residing at Schenectady, county of Schenectady, State 5 of New York, have invented certain new and useful Improvements in Fuse-Boxes of Molded Insulation, of which the following is a specification.

/ This invention relates to thermal cut-outs,

blow-out type patented to F. B; Corey, April 26, 1904, No. 758,172; The box therein shownconsists of a stationary back and ends, with a hinged front and'an open bottom. At each end is .a clampto hold one end of a fuse strip, which isstretched across the upper portion of an arc chute of insulation, having an 'openb'ottom. On each side of the arc chute is a plate of'ir'on, and the ends of said plates are connected by heavy studs of iron which short circuit the magnetic flux below the fuse when a current is flowing therein so that the field of force developed by the current is concentrated above the fuse, in a position to push the are down and out of the-chute when the fuse blws.- I

' The present invention aims to improve the structural details of this kind of a fuse box, and to that. end the entire box is made of molded insulating material, the back, top and ends bein preferably molded in one piece, though is ey may be built up of separate pieces if desired. The front is a sheet of 'insulatin 0 en. 0 ute. In the back and also in the front are embedded plates of iron to induce the magnetic field which blows out the arc. These plates are each com osed of two portions the formation of a short circuit should one side of the box become accidentally connected with a sourceof current. The plates are also continued out throu h the ends of the front and back and fas 'oned into hinge knuckles which aresuitably pivoted together and enable the front to be turned down when a new fuse is to be inserted. These hinge portions take the lace of the connecting 5 studs'which in the (ibrey 'atent short circuit the magnetic flux belo'wt e'fuse.

In the accompanying afront elevation 0 improved fuse box,

' with-thefront turned own; Fig. Zis a cross-' and especially tofuse boxes of the automatic material, and the bottom is left T e box itself thus'forms the are separated by a suite. 1e distance toprevent drawing, Figure 1 is:

section of the same without the cover; and

ing the ends of the fuse 6. The clamps may be of any suitable construction, though I prefer those shown and described in my Patent No. 815,746, grantedMar. 20, 1906, in which a jaw 7 can be drawn by a screw 8 into a seat in a block 9, firmly clamping the end of the fuse between said jaw and seat. The block issecured to the top of the box by the screws 10, and each block has asocket 11 to receive and hold'the end of a lead.

Embedded in the back of the box are two iron plates 12' 13, one being preferably L- shaped and, the other like an inverted L.

They are so laced as. to overlap in the man ner shown," ut with a certain ap between them, which is filled with insu ation. The main portions of theplates stand above the fuse and are double the thickness of the lower end portions 14,.the latter extending to the Two similar L-shaped plates 18 19 8.I6 6IIl-,

bedded the front 20, which is made of insulating material; the plates being set into shallow recesses in the inside of said cover and then covered with a sheet 21 of insulation, secured'by rivets 22. The end portions of the plates are extended at right angles to form t e knuckles 23 which cooperate with .the knuckles 15 and are ivoted thereto by the screws or pins 24:. ien the front is swung up to close the box, it is fastened by a catch consisting referably of a U-shaped wire 25 held loose yin a pocket in an extension of one of the plates, andadapted to engage with a stationary catch-plate 26 fastened to the top of the box by screws 27.

The heads of'the screws may be covered by.

a strip 28 of insulation. riveted to the top of the box; andtthe catch-plate is covered on top by a slab 29 of insulation which also covers the screws 10.

The structure is strong and compact, and by reason of'the gap between the two portions of the plates 12 13 and, 18 19 there is no danger of a short-circuit if one of the plates becomes alive.

- vWhen an electric current traverses the fuse 6 or springs across the space occupied.

thereby in the form of an arc the magnetic lines of force, which are invariably associated with an electric current and normally having circular paths thereabout in perperk dicular planes, seekv the passages of least resistance and accordingly flow through the iron plates 12, 13 and 18, 19 from top to botr tom jumping the air space at. above the conductor or arc and passing through the hinged joints between the lates 12, 18 and 13, 19 so that a magnetic fie d of force is produced at the upper side only of the current. When an arc exists in the place of the fuse 6 the field of force at the upper sidethereof acts in a well known manner to force the arc downwardly until it breaks automatically.

I do not desire to restrict myself to the particular form or arrangementof parts herein shown and described, since it is ap arent that they may be changed andmodified without departing'from my invention.

What I claim asnew, and desire to secure by Letters Patent of the United States, is,

1. A thermal cut-out havin an arc chute, and a pole-piece mounted 'at t e side thereof and composed of portionsseparated by a gap.

2. A thermal out-out comprising an are chute having a divided pole-piece embedded in it.

3. A thermal cut-out comprising an arc chute having a pole-piece embedded in it and extended to form a hinge knuckle.

.4. A. thermal cut-out comprising a box having a pole-piece embedded in it, and a cover having a pole-piece embedded 'in it, said pole-pieces being hin ed together.

5. The combination wit a fuse box, of a cover therefor, and pole-pieces secured to said box and cover and hinged together.

6. The combination with a fuse box, ofa cover therefor, and pole-pieces secured to said box, and cover and hinged together,

each pole-piece being composed of two portions separated by a gap.

7 The combination Withla fuse box of insulating material, of a pole-piece embedded therein, andhaving end portions extending at iight' angles thereto beyond the edge of said s. The combination with a as box, of in-.

sulating material, of a pole-piece embedded therein'having its main portion thicker than the end portions.

ARTHUR? oj SAVAGE.

Witnesses BENJAMIN B. HULL, HELEN ORFoRD'. 

